ST3243C

3 to 5.5 V, 400 Kbps, RS-232 transceiver with auto-power-down The ST3243 device consists of 3 drivers, 5 receivers and a dual charge-pump circuit. The device meets the requirements of EIA/TIA and V.28/V.24 communication standards providing high data rate capability. The receiver R2 is always active to implement a wake-up feature for serial port. The ST3243 has a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a 3.0V to 5.5V supply with a dual charge pump. The device is guaranteed to run at data rates of 250 kbps while maintaining RS-232 output levels. The Auto-power-down feature functions when FORCEON is low and FORCEOFF is high. During this mode of operation, if the device does not sense a valid RS-232 signal, the driver outputs are disabled. If FORCEOFF is set low, both drivers and receivers (expert R2B) are shut off, and supply current is reduced to 1mA. Disconnecting the serial port or turning off the peripheral drives causes the auto-power-down condition to occur. Auto-power-down can be disabled when FORCEON and FORCEOFF are high, and should be done when driving a serial mouse. With Auto-power-down enabled, the device is activated automatically when a valid signal is applied to any receiver input. Typical application are in notebook, sub-notebook, palmtop computers, battery-powered equipment, hand-held equipment, peripherals and printers.1 µA supply current achieved when in auto-power-down250 kbps minimum guaranteed data rateGuaranteed 6 V/µs slew rate rangeGuaranteed mouse drive ability0.1 µF external capacitorsMeet EIA/TIA-232 specifications down to 3 VAvailable in SSOP-28 and TSSOP28

ST3243C